SOME NEW AM) BABE DIATOMS. 



the valve. The present members of the genus may perhaps be referred to Ordspedodiscus, 

 in which transfer Herr Grunow has taken the initial step. All the species are very con- 

 vex: some of them conical, some armed with spines. 



Triceratium coniferum, BrigMwell, Trans. M. S. 1856, p. 274 PL 17 f. 6; 



Pritch. Inf. p. 853; Sch. At. 96 f. 27-31. Valve with radiant lines of cellules covering the 

 surface; centre of valve convex, with straight margins and furnished with from three to 

 nine spines; angles much produced, their margins forming a concavity with those of the 

 central portion; very variable in size, density of punctuation, length of angles and num- 

 bf r of spines: nodules prominent. Distance between angles, .002.") to .0045 inch. Spring- 

 field Estate. Barbadoes. Plate III, Fig. 17. 



Herr Grunow is inclined to place this species in the Genus Trinacria, in which 

 conclusion we concur. 



Triceratiutn lVeissflogii, n. sp., W. and C. Large, sides straight, occasion- 

 ally slightly concave; angles rounded, somewhat acute; margins marked by a row of 

 cellules, giving it the appearance of being beaded by minute projections; angles with 

 a small space filled with minute granules; surface of valve covered with irregular, frac- 

 ture-like lines, forming in the central portion a large hexagon, whose sides extend nearly 

 to the margin, and also separate the angles from the central space: a moderately fine. 

 radiant punctuation filling all the large interspaces. Distance between angles. .0048 

 inch. Springfield Estate, Barbadoes. Plate III, Fig. 2, 3. 



Triceratiutn Hardinaiiiant€tn, Grei\, Trans. M. S. 1865 p. 55 PI. 6 f. 25. 



"Large: valve with straight sides and subacute angles; central spare filled with a some- 

 what hexagonal figure, extending to the margin and furnished with radiating puncta 

 and imperfect radiating costa?: within this, a triangular figure, having a large spine in 

 the centre surrounded by a circle of smaller ones; angles within furnished with puncta 

 and vein-like lines and indistinct pseudo-nodules." Distance between angles, .0044 inch. 

 Springfield Estate, Barbadoes. Plate IV, Figs. 1, 2. 



We are able to present in Fig. 2, a variety of this species, with the internal figure 

 formed by the costa having circular outlines instead of triangular. 



Triceratiutn Westianutn, Grev., Trans. M. S. 1861 p. 43 PI. 4 f . 11; Schm. 

 At 77 f. 30-32; tar. quadrata, 94 f. 10. "Sides of valve deeply and sharply concave: 

 angles forming segments of circles, separated from the centre by transverse lines, margins 



